Strength and deformation characteristics of sand-geosynthetic interfaces through digital image analysis

摘要

Effect of morphological characteristics and size of sand grains and surface features of geosyn-thetics on the strength and deformation characteristics of sand-geosynthetic interfaces were investigated in this study through digital image analysis. A special symmetric loading interface direct shear test-setup which minimizes the boundary effects of interface testing and allows High Definition (HD) image capturing of interface shearing was developed. Systematic series of interface direct shear tests were performed with sands of different sizes and morphological properties interfacing with different geosynthetics, namely geomembrane, geotextile and wire meshes. The interface shear stress- shear strain response of sands with similar morphological characteristics and different grain sizes revealed that with increase in roughness of geosynthetic materials, friction and dilation angles increase substantially. Further, the effect of aperture ratio of the interfacing materials and the surface roughness of the geosynthetic material were found to be governing the interfacial shear strength to a larger extent.